Annealing furnace



Jan. 12 1926.

E. WIRZ ANNEALING FmmAcz Filed Sept. 17 1925 .P MW.

Ill-II -lu 19| .u Q Q Patented Jan. 12, 1926.

UNITED v'STATES 1,569,444 PATENT OFFICE.

ERNST WIRZ, OF BADEN, SWITZERLAND, ASSIGNOR TO AKTIENGESELLSCHAFT BROWNBOVEBI & CIE., OF BADEN, SWITZERLAND.

ANNEALING FURNACE.

Application led September` 17, 1925. Serial No. 56,961.

To all whom t may concern.'

Be it known that I, ERNST WIRz, a citizen of the Swiss Confederation,and resi dent of Baden, Switzerland, h ave invented new and usefulImprovements. 1n Annealing Furnaces,of which the following 1s aspecitication.

This invention relates to annealing fur- 'naces particularly intendedVfor metal plates land sheets.

In order to prevent metal plates and sheets from warping duringtreatment in an annealing furnace .it is essential that the plate orsheet should lie perfectly flat on the hearth or grate bars. This iseasily attained so long as the furnace is at a constant temperature,that is to say during the actual period of annealing and when thefurnace is cold. But during the heating and the cooling of the furnaceunequal expansion and consequent alteration of the shape of the gratebars on which the plate to be annealed is carried may easily occur, andsuch variations are of course transmitted to the plate. Thesedisadvantages become accentuated the larfrer the ldimensions of thefurnace and of the metal plates to be annealed.

By means of the present invention it is possible to construct annealingfurnaces for metal plates and sheets of the largest dimensions and tooperate them in a manner free from objection. The heating is carried outelectrically by means of resistance heaters. In accordance with theinvention the supporting means for the plate which is located in thefurnace chamber and is exposed to the full heat of the furnace, has alevel surface, is constructed of fireroof, non-oxidizable metal, and isattached 1n a yielding manner to a se arate carrying structure arrangedoutside t e hot zone of the furnace. A

One form of construction of an annealing furnace according to theinvention is illustrated by way of example in the accompanying drawingwherein:

Fig. 1 shows a cross section, and

Fig. 2 a longitudinal section.

The plate a to be heated rests upon the upwardly extending beams c whichare arranged in the form of a grate on the hearth b which is closedoverhead. The spaces d between the beams accommodate conveyor means forfeeding the plate into the fur- `resistance wire wound on quartz tubesare arranged above the beams c on the crown of the furnace f andunderneath the heart-h at the bottom of the furnace. In order to preventthe hearth plate b and th beams 0,'which are cast integral therewith,from warping it is secured by strong bolts g, which are of a fireproofand non-oxidizable alloy at least where they are exposed to the heat, tothe carry ing structure whichV consists of beams h arranged as a gratelike structure disposed underneath the brickwcrk at the bottom of thefurnace so that they are protected fromv the heat of the furnace. Strongsprings z' are inserted between the nuts on the bolts and the carryingstructure beams h and tubes lc, of which the upper part must also be ofa fireproof and non-oxldizable alloy, surround the bolts and act asdistance pieces. These yielding connecting members enable unequalexpansion which occurs in spite of the great stability and carryingcapacity of the foundation,

and is caused by the .large differences-in temperature to becounteracted.

What I claim is:-

l. An annealing furnace having supporting means with a level surface fora plate to be annealed located within the furnace chamber and formed offireproof non-oxidizable metal, a carrying structure disposed withoutthe hot zone of the furnace and yielding connecting members connectingthe supporting means and the carrying structure.

2. An annealing furnace having supporting means with a level surface fora plate to be annealed located within the furnace chamber and formed offireproof non-oxidizable metal, a carrying structure disposed withoutthe hot zone of the furnace, spacing members between the supportingmeans and the carrying structure7 and yielding connecting membersconnecting the supporting means and the carrying structure.

3. An annealing furnace having supporting means with a level surface fora plate to be annealed .located within the furnace chamber and formed ofireproof non-oxidizable metal, a carrying structure disposed Without thehot zone of the furnace, tubular spacing members between the supportingmeans and the carrying structure,

The electrical heating elements c l bolts assin tlirou h the tubularmembers P g g and connecting the supporting means and the carryingstructure, and springs interposed between the bolts and the carryingstructure.

4. An annealing furnace having supportin means with a level surface fora plate to be annealed located within the furnace chamber and formed offireproof non-oxidizable metal, a carrying structure consisting of aplurality of beams disposed without the hot zone of the furnace andyielding connecting members connecting the supporting means and thecarrying structure beams.

5. An annealing furnace having supporting means with a level surface fora plate to be annealed located within the furnace chamber and formed ofreproof non-oxidizable metal, a carrying structure consisting of aplurality of beams disposed without the hot zone of the furnace, tubularspacing members between the supporting means and the carrying structurebeams, bolts passing through the tubular members and connecting thesupporting means and the carrying structure beams, and springsinterposed between the bolts and the carrying structure beams.

6. An annealing furnace having supporting means for a plate to beannealed consisting of a plurality of parallel beams mounted on a hearthmember and forming a level surface located within the furnace chamberand formed of reproof non-oxidizable metal, a carrying structuredisposed without the hot zone of the furnace and yielding connectingmembers connecting the supporting means and the carrying structure.

7. An annealing furnace having supporting means-for a plate to beannealed consisting of a plurality of parallel beams mounted on a hearthmember and forming a level surface located within the furnace chamberand formed of fii'eproof non-oxidizable metal, a carrying structuredisposed without the hot zone of the furnace, tubular spacing membersbetween the supporting means and the carrying structure, bolts passingthrough the tubular members and connecting the supporting means and thecarrying structure and springs interposed between the bolts and thecarrying structure.

8. An annealing furnace having supporting means for a plate to beannealed consisting of a plurality of parallel beams mounted on a hearthmember and forming a level surface located within the furnace chamberand formed of fireproof non-oxidizable metal, a carrying structureconsistin of a plurality of beams disposed without t 1e hot zone of thefurnace and yielding connecting members connecting the supporting meansand the carrying structure beams.

9. An annealing furnace having supporting means for a plate to beannealed consisting of a pluralityof parallel beams mounted on a hearthmember and forming a level surface located within the furnace chamberand formed of ireproof non-oxidizable metal,

a level surface located within the furnacey chamber and formed offireproof non-oxidizable metal, a carrying structure consisting of aplurality of beams disposed without the hot zone of the furnace andarranged at right angles to the plate supporting beams, tubular spacingmembers between the hearth member and the carrying structure beams,bolts passing through the tubular members and connecting the hearthmember and the carrying structure beams, and springs interposed betweenthe bolts and the carrying structure beams.

l1. An annealing furnace having supporting means for a plate to beannealed consisting of a plurality of parallel beams mounted on a hearthmember and forming a level surface located within the furnace chamberand formed of fireproof non-oxidizable metal, a carrying structureconsisting of a plurality of beams disposed without the hot zone of thefurnace and arranged at right angles to the plate supporting beams,tubular spacin' members of ireproof non-oxidizable meta between thehearth member and the carrying structure beams, bolts of fireproofnon-oxidizable metal passing through the tubular members and connectingthe hearth member and the carrying structure beams, and springsinterposed between the bolts and the carrying structure beams.

Dated this 2nd day of September, 1925.

ERNST wiRz.

